Why Your Hydroponic Tomatoes May Not Be Turning Red

Dec. 6, 2022

Why Your Hydroponic Tomatoes May Not Be Turning Red

Many hydroponic gardeners face a common problem: their tomatoes aren't turning red. So what could be the reason behind this? There could be a few different causes, but understanding them is essential to growing healthy and happy tomatoes. In this post, we'll explore why your hydroponic tomatoes may not turn red and what you can do to fix the problem. Let's get started! 

The Three Stages of Tomato Ripening

Tomatoes go through three stages of ripening: green, breaker, and red.

  1. The green stage is when the tomato is still hard and has not yet developed any color.
  2. The breaker stage is when the tomato begins to turn yellow.
  3. The red stage is when the tomato is fully ripened and has a bright red color.

Read How to Grow Hydroponic Tomatoes for the Absolute Beginner? to learn more on hydroponic tomatoes growing.

Why Hydroponic Tomatoes May Not Turn Red

You've been carefully tending to your hydroponic tomato plants and finally see some fruit! But there's a problem...the tomatoes are green. What gives? Here are a few potential reasons why your tomatoes may not turn red.

  1. Not enough light -

    One of the most common reasons why hydroponic tomatoes are not turning red is that they are not getting enough light. Tomatoes need at least 8 hours of direct sunlight daily to produce the energy they need to turn red. If your tomatoes are not getting enough light, they will not turn red, no matter how much time you give them.


Move your plants to a sunnier location or supplement natural sunlight with grow lights.  

How to Choose the Right Hydroponic Grow Light for Plants?
The Best Grow Light Strips for Your Indoor Plants
Do Grow Light Colors Matter?

  1. Incorrect temperature -

    Tomatoes will not turn red if the temperature is consistently below 55 degrees Fahrenheit or above 85 degrees Fahrenheit.


Check the temperature of your grow room and make adjustments as necessary to ensure that it stays within the ideal range for tomato production.

Does Grow Light Temperature Matter?
How to Measure EC, pH, DO and Temperature in a Hydroponic System

  1. Lack of nutrients -

    Tomatoes are heavy feeders and require a consistent supply of nutrients to produce red fruit. They need a balance of nitrogen, phosphorus, and potassium to turn red. If your tomato plants are lacking in any of these nutrients, they will not turn red.


Make sure you are fertilizing your plants regularly and supplementing them with additional nutrients if necessary. 

NPK for Hydroponics: How It Works and Why It Matters?
13 Nutrients Required for Hydroponic Plants

  1. Too much water -

    Hydroponic tomatoes also need the right amount of water to turn red. If the roots of the plant are sitting in water that is too deep, it can cause the plant to drown and prevent it from getting the oxygen it needs to produce energy. On the other hand, if the roots are not sitting in enough water, the plant will not be able to get the moisture it needs, and it will also prevent the plant from turning red.


Check the water level in your hydroponic system and ensure the roots are sitting in a few inches of water.

7 Watering Tips for New Hydroponic Gardeners
What Are the 10 Ways to Avoid Over or Underwatering Your Seedlings in Hydroponics?

  1. Disease or pests -

    If your plants are infested with aphids, whiteflies, or other pests, it can prevent them from getting the nutrients they need to turn red. Additionally, diseases such as blight can also prevent tomatoes from turning red.


Treat your plants with an appropriate pesticide or fungicide, and make sure to keep up with regular maintenance.

  1. Genetic factors -

    Some types of tomatoes will not turn red no matter what you do. The good news is that plenty of other delicious varieties of tomatoes will!


Do research and choose a different type of tomato plant to grow next time. 

Read Why Your Hydroponic Tomatoes May Not Be Turning Red to learn more.

Also, learn to be aware when pruning your plants such as lettuce, tomatoes, strawberries by reading 4 Common Mistakes to Avoid When Pruning Your Hydroponic Plants.


If your hydroponic tomatoes are staying green, don't despair! There are a few possible reasons why this may happen; thankfully, there are also solutions. By ensuring that your plants get enough light, water, and nutrients and maintain the correct temperature, you can encourage them to produce beautiful, juicy, red fruit in no time!

Thank you for reading!

Also, read:
How to Grow Hydroponic Basil: A Step-by-Step Guide
How to Grow Hydroponic Lettuce for a Healthy, Delicious Salad?
How to Grow Hydroponic Cucumber: Step-by-Step Guide
How To Grow Hydroponic Potatoes

How we work

Readers support Hydroponic Way. We earn through display ads. Also, when you buy something we recommend, we may get an affiliate commission. But it never affects your price or what we pick.

Connect with us